Screw-cutting tool.



PATENTED JAN. 8, 1907.

B.j.BEoK.

SCREW CUTTING TOOL.

IIIIIIIIIIIIIIIII GT.26, 1905.

xl! Chg! ATTEST: /A/ VEA/TOR.'

yUNITED STATES PATENT wien.

EDWARD E. BECK, OF CHICAGO. ILLINOIS, ASSIGNOR TO NYE TOOL AND MACHINE WORKS, A CORPORATION OF ILLINOIS.

Specification of Letters Patent.

Patented Jan. 8, 1907.

Application filed October 26, 1905. Serial No. 284,442.

To LZ/ whom, t Wray con/cern,.- f

Be it known that I, EDWARD E. BECK, a citizen of the United States of America, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Screw-Cutting Tools, of which the following is a specification.

This invention relates to screw-cutting tools adapted to form either external or internal threads in pipes and like articles, and has for its object to provide a simple and eflicient structural formation and combination of the thread-forming teeth ofthe tool whereby with a minimum degree of frictional resistance to the operation of the tool a very perfect screw-thread is produced with certainty and precision and which at the same time affords a tool having ample clearance for the discharge of the cuttings and is both strong and durable, all as will hereinafter more fully appear.

In the accompanying drawings, illustrative of the present invention as applied to a screw-cutting die, Figure 1 is a rear elevation. Figs. 2, 3, 4, and 5 are detail transverse sections on lines 0c Q0 :r2 x2, and :r3 x3, Fig. l.

Similar numerals of reference indicate like parts in the different views.

Referring to the drawings, 1 represents the body of a die having the usual central aperture or bore carrying the usual instanding die-blades 2, 3, 4, and 5, formed with cutting teeth or serrations, which in the present invention have an arrangement and formation as follows:

6 represents individual full-sized threading-teeth formed on the respective die-blades 2, 3, 4, and 5 immediately to the rear of the usual tapering counterbore or entrance 7 of the die and arranged on a common pitch-line, as shown, the construction affording a series of full-sized threading-teeth immediately back of the die-entrance and the attainment of an easy and correct start in an initial active movement of the die.

8 represents individual seriesof full-sized threading-teeth formed alon the respective die-blades 2, 3, 4, and 5an corresponding in size and form with the initial threadingteeth 6, above described. Each of said teeth 8 are separated from the neXt adjacent teeth a distance equal to the base of a tooth,

that such arrangement of the threadingteeth 8 when used in connection with the before-described arrangement of the initial threading-teeth 6 aords a very strong and durable construction by means of which the tool is guided in a very perfect manner to its work and all tendency to lateral play prevented. With the elimination of such lateral playa strong and durable tool results, in that a lateral play of a screw-cutting tool is the main cause of the breaking and stripping ofthe teeth in actual use. At the same time the operation of the tool is much easier and more precise than would be the case where thedtool is capable of the lateral play aforesai The described arrangement of the series of threading-teeth 6 and 8 is applicable to screwcutting taps and the like, and it is within the scope of the present invention to so apply the same.

Having thus fully described my said invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A screw-cutting tool having a series of blades provided with threading-teeth, each blade having at the front end of the tool one or more initial threading-teeth, said initial threading-teeth on the several blades being in pitch-line with each other, and each blade having part of its teeth in rear of said initial threading-teeth removed.

2. A screw-cutting tool having a series of blades provided with threading-teeth, each blade having at the front end of the tool one or more initial threading-teeth, said initial threading-teeth on the several blades being in pitch-line with each other, and each blade having its alternate teeth in rear of said initial threading-.teeth removed.

3. A screw-cutting tool provided with a series of blades formed with threading-teeth, the initial threading-tooth of each blade back of the forward end of the tool being full size and on a pitch-line one with the other, the remainder of the threading-teeth being separated from each other a distance equal to the IOO base of a tooth With each circular series of said teeth arranged on a eoniinon piteh-line- 4. A screw-cutting tool having a series of instanding blades provided with threadingteeth, each blade having at the front end of the tool one or more initial threading-teeth, said initial threading-teeth on the several blades being in pitch-line with each other, and each blade having part of its teeth in the rear of said initial threading-teeth removed.`

5. A screw-Cutting tool having a series of instanding blades provided With threadingteeth, each blade having at the front end of the tool one or more initial threading-teeth, said initial threading-teeth on the several blades being in pitch-line with each other, and each blade having its alternate teeth in rear of said initial threading-teeth removed.

6. A screw-cutting tool comprising a toolbody having a central aperture formed with 'an entrance-counterbore and a series of instanding blades, the initial threading-tooth of each blade back of said oounterbore being full size and on a pitch-line one With the other, the remainder of the threading-teeth of the blades being separated from each other a distance equal to the base of a tooth with each circular series of said teeth arranged on a ooinnion itch-line.

Signed at Chicago,` .llinois, this 23d day of October7 1905.

ED/VARD E. BECK.

/Vitnesses:

ROBERT BURNS, M. H. HOLMES. 

